Woman Killed Self, 2 Children When She Walked Into Traffic on Interstate

A woman with a history of mental illness purposely walked her young niece and nephew into oncoming interstate traffic to commit a double-murder suicide, a prosecutor said Friday.

Marcelle Thibault, 39, was driving south on Interstate 495 in Lowell last week when she turned the car sharply, drove across the median and northbound lanes and began driving against traffic in the breakdown lane, authorities said.

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She then stopped the car, removed her clothes and undressed the children, took both of them into her arms and walked onto the highway. She and the children were struck by two cars and killed.

"There are not many other scenarios I can think of that are as tragic as this one," District Attorney Gerry Leone said. "It is beyond belief, it is unimaginable, it is unspeakable, and it was a horrible tragedy."

The young victims were Kaleigh Lambert, 5, and Shane Lambert, 4, of Brentwood, N.H., who were the children of Thibault's twin sister.

Thibault, of Bellingham, was a stay-at-home mom who was active with her church and loved to be with her own two teenage children. She was one of eight daughters and loved organizing family gatherings.

Leone said Thibault had picked up the youngsters Jan. 11 for a "pirate and princess weekend." Young said the woman, who had two teenage children, often took her sister's kids for special weekends.

Kaleigh and Shane were the only children of Ken and Danielle Lambert and were typical youngsters, family spokesman Paul Young said. "They're a great family," Young said.

In New Hampshire, a neighbor said the Lamberts were caring, conscientious parents. When their children drew with chalk, they would draw a line halfway down the driveway to mark how close they could go to the street, he said.

Leone said Thibault had received treatment for mental illness. Young described it as an isolated incident in her life, within the past year.

"She appeared to be fully recovered from that, and there was no indication of a relapse," he said.

Leone said no drugs or alcohol were involved. "It is far too complicated, too complex a dynamic and illness for us to be able to make any real determinations about what exactly the cause was or what exactly was in her mind," he said. The drivers of the vehicles were not injured.

A statement from the family released by Leone's office pleaded for prayers and privacy.

"This is a time of terrible tragedy for our families. We love Marci, Kaleigh, and Shane and we miss them very much," the statement said. "We ask everyone to join us in prayer for their souls, and to help us get through this most difficult period of our lives."